Ethylene Rotation in Chiral Octahedral Rhenium(I) Complexes
2001; American Chemical Society; Volume: 20; Issue: 8 Linguagem: Inglês
10.1021/om000865l
ISSN1520-6041
AutoresLee A. Friedman, Scott H. Meiere, Benjamin Brooks, W. Dean Harman,
Tópico(s)Catalysis and Oxidation Reactions
ResumoA series of complexes of the type [TpRe(CO)(LD)(η2-ethylene)] has been synthesized, where LD is tBuNC, PMe3, pyridine, 1-methylimidazole, or NH3 (increasing in electron-donating ability of LD). The rates of the propeller-like rotation of ethylene about the ethylene−rhenium bond have been determined using spin saturation transfer experiments at low temperatures (−85 to −60 °C). It was found that the ΔG⧧ values correlate with both the C⋮O stretching frequencies and Re(II/I) reduction potentials for these complexes, indicating that the barrier to rotation is primarily electronic in nature.
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